Particle beam irradiation apparatus and control method of the particle beam irradiation apparatus

Abstract

Provided is a particle beam irradiation apparatus capable of highly reliable measurement of a dose of each beam and capable of highly sensitive measurement of a leakage dose caused by momentary beam emission. The particle beam irradiation apparatus according to the present invention includes: an emission control portion that controls emission and termination of a particle beam; a control portion that sequentially changes an irradiation position of the particle beam relative to an affected area; first and second dosimeters that measure dose rates of the particle beam directed to the affected area; and an abnormality determination portion that accumulates the dose rates output from the first and second dosimeters for each of predetermined determination periods to calculate first and second sectional dose measurement values and that performs second abnormality determination of determining that there is an abnormality and outputs an interlock signal for terminating the emission of the particle beam in at least one of a case in which the first sectional dose measurement value exceeds a predetermined first reference range and a case in which the second sectional dose measurement value exceeds a predetermined second reference range.

Description

TECHNICAL FIELD[0001]The present invention relates to a particle beam irradiation apparatus and a control method of the particle beam irradiation apparatus, and particularly for directing a heavy particle beam of carbon, a proton beam, or the like to an affected area to treat cancer.BACKGROUND ART[0002]Today, cancer is the highest cause of death, and more than 300,000 people die of cancer every year. Under the circumstances, a particle radiation therapy using a carbon beam and a proton beam with excellent features of high therapeutic effects and few side effects is drawing attention. In the therapy, a particle beam emitted from an accelerator can be directed to cancer cells to destroy the cancer cells while reducing influence on normal cells.[0003]In the therapeutic method, a currently used particle beam irradiation method is a method called a broad beam method. In the broad beam method, a diameter of the particle beam is expanded to a size greater than the affected area based on a ...

AI Technical Summary

Benefits of technology

[0025]According to the particle beam irradiation apparatus and the control method of the particle beam irradiation apparatus of the present invention, highly reliable measurement of a dose of each beam is possible, and highly sensitive measurement of a leakage dose caused by momentary beam emission is possible.

Problems solved by technology

However, the broad beam method is not capable of precise three-dimensional adjustment of the beam in accordance with the shape of the affected area, and there is a limit to reducing the influence on the normal cells around the affected area.

The geometric collimator and the compensator are created for each affected area (and for each irradiation direction relative to the affected area), and there is a problem that radioactive wastes are generated after therapeutic irradiation.

A weak point of the spot scanning irradiation is that the beam emission cannot be actually immediately terminated even if the beam emission control apparatus outputs the beam termination command.

This is particularly a problem when the irradiation dose (set dose) for each point is small, because a ratio of the leakage dose (leakage dose / set dose) is large.

However, the reduction in the beam intensity leads to an increase in the time for treatment, and a physical burden of the patient increases.

Therefore, the irradiation points are relatively deviated along with the movement of the region caused by respiration, and a dose distribution becomes non-uniform.

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